Mobile lift



G. J. BAUDHUIN Oct. 23, 1962 MOBILE LIFT 4 Sheets-Sheet l Filed Sept. l0. 1959 fm1/gw ft2/L M M, @y www WM f M12 l Af- Oct. 23, 1962 c;f J, BAUDHulN '3,059,782

MOBILE LIFT Filed Sept. l0, 1959 4 Sheets-Sheet 2 OC- 23, 1962 G. J. BAUDHUIN 3,059,782

MOBILE LIFT Filed sept. 1o, 1959 4 Sheets-Sheet 3 lfm/mm mig-'v' am @MW M' Oct. 23, 1962 Filed Sept. l0, 1959 G. J. BAUDHUIN MOBILE LIFT 4 Sheets-Sheet 4 United States Patent Oli 3,059,782 Patented Oct. 23, 1'962 .Lice

3,059,732 MOBILE LIFT George J. Baudhuin, Sturgeon Bay, Wis., assignor t Drott Manufacturing Corporation, Milwaukee, Wis., a corporation of Wisconsin Filed Sept. 10, 1959, Ser. No. 839,175 8 Claims. (Cl. 212-13) This invention relates to novel and useful improvements in mobile lift devices.

An important object of this invention is to provide an improved gantry type mobile lift device which is adapted for use over uneven surfaces and which will enable the ground engaging wheels of the gantry to conform to the surface without causing twisting of the bridge portion of the gantry.

A more particular object of this invention is to provide an improved gantry type lift device including spaced side frames and a connecting bridge in which the bridge is rigidly connected to one of the side frames and is pivotally attached to the other of the side frames for limited pivotal movement about an axis parallel to the longitudinal axis of the bridge to permit limited relative turning of the side frames as the gantry traverses uneven surfaces.

Another object of this invention is to provide a gantry type mobile lift device having a carriage mounted on the bridge for movement therealong and an improved traversing and hoisting apparatus in which the traverse winch and the hoist winch `are mounted on a stationary portion of the gantry and connected to the carriage by flexible cables in such a manner that, when the hoist winch is stationary, the carriage can be moved along the bridge without changing the elevation of the load carried by the carriage.

These, together with various ancillary objects and advanges of this invention will be more readily appreciated as the same becomes better understood by reference to the following detailed description when taken in connection with the accompanying drawings wherein:

FIGURE l is a perspective View of the mobile lift dev1ce;

FIG. 2 is a diagrammatic plan view illustrating the use of two mobile lift devices in tandem to transport long objects;

FIG. 3 is an end elevational view of the mobile lift device;

FIG. 4 is a fragmentary sectional view taken on the plane 4 4 of FIG. 3 and illustrating the hoisting and traversing apparatus;

FIG. 5 is a fragmentary sectional view taken on the plane 5 5 of FIG. 3;

g FIG. 6 is a fragmentary sectional view taken on the plane 6-6 of FIG. 3;

FIG. 7 is a fragmentary top. plan View of the mobile lift device;

FIG. 8 is a fragmentary sectional view taken on the plane IS--S of FIG. 7; and

FIG. 9 is a diagrammatic View illustrating the control system for the mobile lift device.

In general, the mobile lift device comprises a gantry type crane having spaced side frames 10 and 11 and a bridge 12 extending between the upper ends of the side frames. The gantry is supported on wheels 13 and 14 to enable movement of the gantry, and a hoist carriage 15 is mounted for movement along the bridge 12.

The side frame 10 comprises a longitudinally extending frame member 18 and upwardly extending frame members 19 and 20. The longitudinally extending frame member 18 is herein shown formed by opposed channels which are spaced apart and interconnected by web Iplates 18a. The upwardly extending members 19 and 20 have their lower ends interposed between the channels and are rigidly secured thereto. The side frame 11 is similarly constructed and includes a longitudinally extending member 21 and upwardly extending members 22 and 23. The longitudinal member 21 is also formed by opposed channel members which are spaced apart by web plates 21a.

The bridge 12 is preferably formed by two spaced beams 28 and 29` which arerigidly attached at one end to one of the side frames such as side frame 10i. As best shown in FIGS. 1 and 4, a plate 31 is secured, as by welding, to the ends of the beams 28 and 29. The plate extends between the beams 28 and 29 to interconnect the same and also projects downwardly below the beams for attachment as by fasteners 32 to the upper ends of the upwardly extending members 19 and 20 to rigidly interconnect the latter to each other and to the bridge. Upper and lower plates 33 and 34 and a side plate 35 are welded to each other and to the plate 31 and extend between the beams 28 and 29 to form a rigid box-type structure for interconnecting the beams. Reinforcing brackets (FIG. 4) 37 are secured to the upper ends of the side frame members 19 and 20y and to the bridge beams 28 and 29.

The bridge 12 is thus rigidly connected to the side frame 10 and Iforms a rigid unit therewith. In order to adapt the gantry-type mobile lift for use on uneven surfaces, the bridge 12 is mounted on the other side framev 11 for pivotal movement with respect thereto about an axis extending parallel to the longitudinal axis of the bridge. This permits the side frames 10 and 11 to turn relative to each other about an axis extending transverse to the axis of the gantry to thereby enable the ground engaging wheels to ride over uneven surfaces without twisting the bridge. For this purpose, a cross beam 40 is secured to the ends of the bridge beams 28 and 29 to extend therebetween. As best shown in FIGS. 4 and 5, the cross beam includes spaced side plates 41 and 42, a bottom plate 43 and top plates 44 and 45 which are secured to each other as by welding to form a box-type structure which extends between the bridge -beams 28 and 29 and rigidly interconnect the same. Plates 47 and 48 are rigidly secured as by fasteners 49 to opposite sides of the side frame members 22 and 23 to rigidly interconnect the latter, which plates have upwardly extending portions 47a and 48a respectively ldisposed at opposite sides of the cross :beam 40. A plate 52 (see FIGS. 4 and 5) is welded to the plates 47 and 48 and extends therebetween. The cross beam of the bridge is pivotally attached to the upwardly extending portions 47a and 48a of the plates by means of a pin 55 which extends through aligned openings in the plates 48, 41, 42 and 47. The openings in these plates are suitably reinforced by bearing plates as shown in FIGS. 4 and 5 which are welded tothe respective plates to increase the bearing area. Spacers 61 are interposed between the cross beam of the bridge and the plates 47 and 48 of the side frame to provide a yworking clearance therebetween. Conveniently, the pin 55 may be held in position by a rigid flange 63 on one end and a removable plate 64 which is detachably secured to the other end of the pin. As will be noted, the axis of the pin is located medially between the bridge beams 2S and 29 Iat a level intermediate the upper and lower edges thereof.

Provision is made for both driving and steering the gantry and in theernbodiment shown, one set of wheels designated 13 are xedly mounted on the frame while the other set of wheels 14 are mounted for steering movement, it being understood that both sets of wheels may be mounted for steering movement if desired. The wheels 13 are rotatably journaled on axles carried by wheel mounting brackets 71 attached to the longitudinally extending members 18 and 21 of the side frames. The brackets herein shown are of generally U-shape configuration and straddle the wheels 13. The other wheels 14 are rotatably mounted on axles carried by wheel supporting brackets 72, which brackets are mounted for steering movement about an upright axis. As best shown in FIG. 6, the brackets each have an upwardly extending shaft 73 thereon which extends through openings in plates 74 and 7S on each of the longitudinally extending members 18 and 21 of the side frames. The brackets 72 are also conveniently in the form of U-shaped yokes -which straddle the wheels 14. Steering of the wheels 14 is preferably effected by an hydraulic steering apparatus of the type disclosed and claimed in the copending application of George Baudhuin, Serial No. 823,766, filed June 29, 1959. In general the steering apparatus includes an hydraulic steering booster 77 such as the series S23 steering booster manufactured by Vickers Incorporated, Detroit, Michigan. One of these steering boosters is provided for each of the yokes 72 and includes a cylinder 78 having a piston therein. The piston rod 79 is pivotally attached by an anchor ball stud 80 (FIG. 3) to a respective one of the side frames. A 4-way control valve 82 is mounted on each of the steering cylinders 77 for movement therewith and has a control ball stud 83 which is movable relative to the control valve from a neutral position to an extend position or a retract position. The steering cylinders at relatively opposite sides of the mobile lift are connected through a bracket 84 to the respective steering yokes 72, at points spaced outwardly of the pivot axis of that yoke. In order to turn both wheels 14 in the same direction, it is necessary to extend one of the steering boosters and simultaneously retract the other steering booster.

The control ball studs 82 of the steering boosters at each side of the lift are operatively interconnected so as to synchronize the operation of the two boosters. For this purpose, a pair of upright steering rods 91 and 92 are provided on the side frames and 11 respectively. The rod 91 extends generally upright and is journaled adjacent its lower end in a bracket 93 (see FIG. l) and at its upper end in a bracket 94 on the side frame 10. The steering rod 92 is similarly journaled at its lower end in a bearing bracket 95 (FIG. 5) and at its upper end in brackets 96 attached to the end of the bridge 12. Upper steering arms 97 are provided on the rods 91 and 92 and a tie bar 98 extends between the upper arms and is supported intermediate its ends on brackets 99 (see FIG. 1) carried by the bridge. Lower steering arms 101 are provided on the lower ends of the rods 91 and 92 and are connected by links 102 to arms 103 attached to stub shafts 104. The shafts 104 are supported on the respective side frames at a point spaced outwardly of the pivot axis of the respective yokes and have arms 105 attached thereto and connected through links 106 to the control ball studs of the respective steering boosters. An operating lever 107 (see FIG. l) is connected through a shaft 103 to one of the stub shafts 104. As will be noted, operation of the lever 107 will, through the interconnected link-age, move the control valves of the respective boosters in relatively opposite directions to extend one booster and simultaneously retract the other booster. Since the side frame 11 is pivotally attached to the bridge '12, universal joints 111 and 112 and a slip joint 113 (FIG. 3) are provided in the steering rod 92 to accommodate the relative turning between the side frame 11 and the bridge 12, which maintaining the driving connection between the steering boosters.

The mobile lift may be propelled in `any suitable manner and as herein shown hydraulic drive motors 114 are mounted by brackets 115 on the steering yokes 72 and are operatively connected through a chain and sprocket drive -116 to the respective wheels 114 :to drive the same. Fluid for operating the boosters and drive motors is preferably provided from a pair of pumps 121 and 122 (FIG. 9) driven as by a gasoline engine 123 `mounted on one of the side frames 10. The pumps have inlet lines 125 and 126 connected tto a reservoir 124 and delivery lines 128 and 129. The delivery lines 128 is connected through a line 130 to the control valve 82r of the right steering booster 77. The other discharge line 129 is connected through a conduit 131 with the left hand control valve 82L of the steering booster at `the left hand yside of the lift. The respective right and left hand control valves are otherwise connected through return lines 132 and 133 with the reservoir 124. The discharge line 128 is also connected through a line 136 to a control valve 13711, which control valve is otherwise connected through return lines 138 and 139 to the reservoir. The valve 137a has controlled outlet ports connected through lines 143 and 144 to the left drive motor 114L, and an operator 142 adapted in one position to connect the supply line 136 with the line 143, and in the other position to connect the supply line with the line 144 to thereby reversibly drive the motor. Preferably, the valve is of the type having a neutral position in which it intercommunicates the lines 143 and 144 to provide free wheeling. The delivery line 129 is connected through a conduit 148 with a `control valve 137b, which control valve is otherwise connected Ithrough a line 149 with the return line 139 leading to the reservoir. The valve 137b has controlled outlet ports connected through conduits 151 and 152 to the right hand drive motor 114r and a control lever 153 for reversibly controlling -the application of pressure to the motor 1141. As will be noted, the right hand steering booster and drive motors are operated from one pump and the left hand steering booster and drive motors are operated from a separate pump.

The traverse carriage mounted on ,the bridge 12 includes a generally rectangular frame having parallel side members 155 and end members 156. Intermediate members 157 are secured to the side members and extend parallel to the end members and trolley wheels 158 are journaled between the intermediate members and the adjacent end members 156. The trolley is supported on tracks 159 carried by the bridge beams 28 and 29, and Stops 160 are provided at the ends `of the tracks. Cross members 162 are secured to the intermediate members 157 to extend therebetween and in parallel relation to the side members 155.

A traverse winch 164 is mounted on bearings 165 at one end of the bridge and driven through a reduction gear 167 from lan hydraulic motor 168. A traverse pulley 169 is mounted by a bracket 170 at the other end of the bridge. A cable 171 has a number of turns around the traverse winch 164 and has one end thereof 171a attached to `the carriage, as by an adjustable eye bolt 173. The cable extends through a guide tube 174 on the upper side of the carriage and over the pulley 169 and has the other end 1711; 'attached to the carriage as by an adjustable eye bolt 175. The eye bolts are adjusted to maintain the cable 171 under tension so that, when the traverse winch 164 is operated, it will move the carriage along the bridge in the direction determined by Ithe direction of rotation lof the hydraulic motor 168. As diagrammatically shown in FIG. 9, this motor is connected through lines 177 and 178 to :the controlled outlets of `a valve 179. Fluid is supplied to the valve as from the supply line 128 through a conduit 181, and the return of the valve is connected through a line 182 to the sump line 139. The valve 179 has an operator 183 which will reversibly control Ithe flow of uid to the traverse motor 168 and reversibly operate `the carriage.

In laccordance with the present invention, the hoist winch is mounted on the side frame 10 and it is connected Ito the carriage in such a manner that movement of the carriage along the bridge does not alect the elevation of the articles carried by the hoist. In particular, the hoist winch includes drums and 191 which are rotatably journaled in bearings 192 carried by cross arms 193 on `the side frame 10. An hydraulic drive motor 194 is connected to a reduction gear 195 also mounted on the cross arms 193, and which reduction gear has a drive sprocket 196 connected through a chain 197 to a driven sprocket 198 on the hoist winch shaft. A pair of spaced idler pulleys 201 and 202 are mounted on :a bracket 203 at one end of the bridge 12. A horizontally disposed pulley is located at the other end of the bridge and mounted for rotation about `an upright pin 205 on the bracket 170. Idler pulleys 206 vare disposed adjacent the periphery of the pulley 204 to guide the cable as it enters and leaves the main pulley. A cable 207 has the ends thereof attached to the Winches 190 and 191. and extends upwardly over the pulleys 201 `and 202 and then lengthwise of the bridge 12 and around the pulley 204 `at the opposite end thereof. The horizontally extending runs 207a and 207b which extend lengthwise of the bridge, are entrained over a tackle suspended from the carriage. In the form shown herein, the tackle includes a lirst set of three sheaves Sa-208c, and ya second set of three sheaves designated 209a-209c mounted on a shaft 211 supported in a bracket 212. The sheaves, las best shown in FIG. 7, are mounted -for rotation Iabout an axis extending crosswise of the bridge 12 and located medially between the beams 28 and 29 thereof. A tackle block 215 is suspended below the' carriage and includes a iirst set of two pulleys designated 21611 and 216b and a second set of two pulleys 217:1 rand 217b. The pulleys 216 and 217 rare mounted on la common shaft 218 which parallels the shaft 211. The tackle box 215 is formed by a plurality of plates 219 which extend downwardly from the shaft on which are maintained in parallel spaced relation by a bolt 220 and spacers 221. An eye plate 222 is suspended from the bolts 220 and has an opening 223 therein for the reception of a chain or the like by which the yarticles 'are attached to the pulley block. As

shown, the run 207e of the cable is entrained over the carri-age pulley 208a, thence over the block pulley 216a, upwardly over the carriage pulley 208b and then over the block pulley 216b and then upwardly over the carliage pulley 208C. The other run 207b of the cable is entrained over the carriage pulley 209a, and extends downwardly Iover the block pulley 217a, then upwardly over the carriage pulley 209b, zand downwardly over the block pulley 217b and finally upwardly over the carriage pulley 209e. The cable, as previously described, extends from the carriage pulleys 208e` and 209C longitudinally of the bridge 12 and Iaround the pulley 204 at the end thereof. As will be noted from FIG. 7, the idler pulleys 206 maintain the runs of the cable spaced apart a diS- tance corresponding 'to the spacing between the pulleys 208e and 209e. Guides 224 may be provided on the carriage for guiding the runs 207a and 207b onto the pulleys 208a and 209a respectively. With this arrangement, when the winch drums 190 and 191 are rot-ated in a direction to Wind the cable 207 thereon, the pulley block 215 and the load carried thereby will be elevated. Conversely, when the drums `are :turned to unwind the cable 207, the pulley block will be lowered. However, when the hoist drums are stationary, the carriage can be moved Ialong the bridge without changing the elevation of the load. As diagramm-atically shown in FIG. 9, the hoist motor 194 is connected through conduits 231 and 232 to the controlled outlets of a 4-way valve 233. 'Ille inlet of the valve is connected as through a conduit 234 to the pressure outlet line 129 of one of the pumps 122, and the valve is otherwise connected to the reservoir through a conduit 235 and return line 139. The valve 233 has an operator 236 for reversibly controlling the ow -of fluid to the hoist motor 194 and, preferably, the valve is of the type which has `a neutral position and which it blocks flow to land form the lines 231 and 232 to aid locking the hoist motor against rotation.

From the foregoing it is thought that the operation and construction of the device will be readily understood. As is apparent, the gantry type mobile lift is self-propelled and is steerable to enable maneuvering of the device. When the lift traverses an uneven surface, the side frame 10 and 11 'are adapted to turn relative to each other about the pivot pin 55 so that all four groundengaging wheels may cont-act the surface to provide adequate traction and to prevent twisting of the bridge 12. This also prevents distortion of the carriage tracks 159 which are canried by the bridge beams 28 and 29. Since the traverse winch 164 land the hoist Winches 190 and 191 are mounted on the frame Iof the lift, the Winches do not move with the carriage and it is accordingly unnecessary to provide elongated flexible conduits for connecting the traverse winch land hoist lwinch drive motors yto the respective pumps. By reason of the cable and pulley arrangement employed for the hoist winch, the carriage can be moved along the bridge by the traverse winch without changing the elevation of the pulley block 215 yand the load carried thereby.

The gantry type mobile lift may be used singly to handle lrelatively short articles or in tandem ras shown in FIG. 2 to handle very long articles such as prestressed concretel beams 245 and the like Iwhich must be handled for the ends thereof. 'Ihe mobile lift is very maneuverable and, in conjunction with the transversely movable carriage 15, is Aadapted to accurately position the load lcarried thereby. When operated in tandem, two operators, one on each lift, may be 'conveniently employed to manipula-te the variols control valves on each lift. Alternatively, the `control valves 137:1 and 137b for Ithe drive motors 114 on each of the lifts can be set in its neutral position -to ,enable one mobile lift to trail the other.

I claim:

1. A gantry comprising spaced side frames, an elongated overhead bridge extending between said side frames, means rigidly attaching one end of said bridge to one side frame, pivot means attaching the other end of the bridge to the other side frame for limited pivotal movement relative thereto -about an axis parallel to the axis of the bridge, `and ground engaging wheels mounted on each of the side frames to support the gan-try, said pivot means permitting one side frame to turn 'about said axis relative to the other `frame when the gantry traverses yan uneven surface to thereby prevent twisting of said bridge.

2. A gantry comprising spaced sidel frames, an elongated overhead bridge extending between s-aid side frames, -means rigidly attaching one end of said bridge to one side frame, pivot means lattaching the other end of the bridge to the other side frame for limited pivotal movement relative thereto about an laxis parallel to the axis of the bridge, ground engaging Wheels mounted on each of the side frames to support the gantry, said pivot means permitting one side frame to turn 'about said axis relative to the other frame when the gantry traverses an uneven surface to thereby prevent twisting of said bridge, a carriage mounted on said bridge for movement therealong, and hoist means suspended from said carriage for elevating `and lowering articles.

3. A gantry comprising spaced side frames, an elongated overhead bridge extending between said side frames, said bridge including spaced parallel beams attached at one end to one of said frames, pivot means attaching the other ends of said beam-s to the other side frame for limited pivotal movement relative thereto about an axis parallel to said beams, and ground engaging Wheels mounted on each of said side frames to support the gantry, said pivot means permitting one side frame to turn relative to the other side frame about said axis when the gantry traverses an uneven surface to thereby prevent twisting of said bridge.

4. The combination of claim 3 wherein said p-ivot axis is located medially between said parallel beams intermediate the upper and lower edges thereof.

5. The combination of claim 4 including a carriage having spaced wheels mounted on said spaced beams` for movement along said bridge, and hoist means suspended from the carriage.

6. A gantry comprising rst and second spaced side frames, an elongated overhead bridge extending between said side frames, said bridge including spaced parallel beams attached at one end to said first frame, a crossbeam extending between the other ends of said beams and rigidly interconnecting the Same, spaced bearing brackets on the upper end of said second side frame extending upwardly on opposite sides of said cross-beam, pivot means mounting said cross-beam on said bearing brackets for pivotal movement about an axis extending parallel to said ybeams and located between said beams intermediate the upper and lower edges thereof, first and second sets of wheels respectively mounted on the ower ends of said first and second side frames, at least one of the wheels of each set being mounted for steering mover ment about an upright axis, steering means for turning said last-mentioned wheels, and means for driving at least one of the wheels of the gantry to propel the same, said pivot means permitting one side frame to turn relative to the other side frame about the axis of said pivot means to permit a1l of the wheels to contact the ground and to permit all of the wheels to contact the ground and to prevent twisting of the bridge when the gantry traverses an uneven surface.

7, The combination of claim 6 wherein said steering means includes a pair of upwardly extending steering rods each mounted on one of the side frames, arms on the upper ends of the rods, and a tie rod extending between said arms, said steering rod on said second frame including a universal joint and a slip joint to accommodate relative pivotal movement between said second frame and said first frame.

8. A gantry comprising rst and second spaced side frames, an elongated overhead lbridge extending between said side frames, means rigidly attaching one end of said bridge to `said rst side frame to form a rigid unit therewith, pivot means attaching the other end of said bridge to said second side frame for limited pivotal movement relative thereto about an axis parallel to the axis of said bridge, first and Second sets of ground engaging wheels mounted on each of the side frames to support the gantry for movement, said pivot means permitting said first and second side frames to turn relative to each other about said pivot axis when the gantry traverses an uneven surface and thereby prevent twisting of said bridge, a carria-ge mounted on said bridge for movement therealong, means mounted on said rigid unit Iand connected to said carriage for moving said carriage along said bridge, a pulley mounted on said bridge adjacent said other end thereof, a set of sheaves mounted on said carriage for rotation about an axis transverse to the direction of movement thereof, a tackle block, a hoist winch mounted on said rigid unit, and a cable attached to said hoist winch and entrained intermediate its ends over said pulley and over the sheaves on said carriage and said tackle block to enable movement of the carriage along the bridge without changing -the elevation of said tackle block.

References Cited in the lile of this patent UNITED STATES PATENTS 594,304 Wellman Nov. 23, 1897 1,382,614 Aveling June 28, 1921 2,343,014 Langan Feb. 29, 1944 2,506,930 LeTourneau May 9, 1950 2,574,473 Getz Nov. 13, 1951 FOREIGN PATENTS 619,042 Great Britain Mar. 3, 1949 

